<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>

        .container{
            width: 400px;
            height: 400px;
            background-color: yellow;
        }
    </style>
</head>
<body>
    
    <input type="text" class="main"/>

    <div class="container"></div>

    <script src="DOM2.js"></script>
</body>
</html>